Lamp socket rheostat



Sept. 19, 1933; c. L. WEICHELT' 1,927,301

LAMP SOCKET RHEOSTAT Filed Feb. 10, 1930 lNV NTOR 45 QM. ad M Patented Sept. 19, 1933 1,927,301 LAlvm'socKET RHEQSTAT Carl LJ-Weichelt, Philadelphia, Pa., assignor to Wirt Company, Philadelphia, Pa., a corpora.-

tion of Maine Application February 10, 1930. SerialNo. 427,16$" V 13 Claims. (01. 201-49) The present invention relates to attachments for incandescentlamps by means of which the flow of current to the filament may-be regulated and the intensity or candlepower of the light produced thereby controlled.

An, object of the invention is to provide such a device in which the parts thereof are so constructed as to enable themto be cheaply manufactured and easily assembled into a compact, durable reliable, and otherwise satisfactory unit, the latter being appropriate; particularly for use with fixtures in which a lampsocket is enclosed within an ornamental protecting jacket member which may be secured to anothersuitable support or which may comprise part of a lighting fixtin'e.

The invention is directed more particularly to provide a current reducing device, including a lamp socket and a rheostat fixed in axial alinement thereto, said connected parts being readily inserted longitudinally in a tubular member which may form a part of an ornamental fixture.

A further feature of the invention is the'provision of a sliding contact arrangement which insures the maintenance of a positive and efficient engagement of a rotatable switch-wiper arm with theco-operating stationary contacts.

Briefly, these objects are accomplished by an arrangement of parts in which a tubular rheostat ring is connected in axial alinement with a lamp socket and a rotatable shaft extends axially through the ring and carries flexible switching means adapted to engage the rheostat terminals and the center contact of a lamp simultaneously.

Other objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing, in which Fig. 1 is a view partly in elevation and partly in section'of a dimmer or lamp socket rheostat illustrating one embodiment of the invention; Fig. 2 is a vertical section view ofthe dimmer with the enclosing jacket and the lower operating knob removed, taken along the plane indicated by the line 2--2 of Fig. 1; Fig. 3 is asimilar vertical sectional view taken. at right angles to Fig. 2, as indicated, by the line 33 of Fig. 2; Fig. 4 is a horizontal sectional view of the complete device looking downwardly on the plane indicated by the line 44 of Fig. 2; and Fig. 5 is a perspective view of the operating shaft and rheostat switching means associated therewith. The drawing illustrates an electrical fixture of a type with which a device embodying the invention is particularly adapted to be used, comprising a tubular jacket 8 and its supporting member 9, composed of a molded or baked in- 6 sulating material, such as porcelain. The parts towhich the present invention is directed comprisethe electric lamp socket luandthe associated dirnmer 11-, removably mounted in, but rigidly secured to; the jacket 8. The lamp socket 10 may be of -the standard screw-threaded type, and to the base of-thisshellis mounted an insulating disc -12..;, The latter carries a flexible contactor l5 which'rnay, be secured thereto by the rivet 16. The contactor 15 extends within the socket 10 for engagement with the end or center terminal of a lamp inserted the socket and the rivet 16 co-operates with the switching means of the associated dimmer.

In the general form of deviceto which the invention relates the desired currentreduction is produced by the vuse ota fixed rheostat having terminals adapted tobe successively engaged by a moving contact or wiper. to complete a series circuit including a source of potential and a lamp filament. In the present embodiment-of the in vention, l have shown the rheostat as a tubular member l-l, composedof a molded or baked insulating -material, on .the peripherypf which is wound aresistancecoil 19 having its ends anda point intermediate tl 1e .latte r connected ICSPQC'. tively to terminals 21, 23 and 22 disposed at the 8 upper end of the rheostat. The coil 19 maybe coated with a cemental composition. not shown in the drawings, which.embeds said coil 19 in a in a layer of insulatingmaterial. The terminals 21, 22 and 23 may conveniently take the form of screws extending through longitudinal openings formed through the member 17, the heads of said screws providing the terminal contacts at the upper end of said member 17 for co-operation with the switching means, which will be later described. The tubularmember 1' 7 .is formed with an arcuately disposed recess .13;- at its lower end, which recess provides seating ledges for the nut si21-a and ,23a which co-operate, respectively, with the terminal screws 21 and 23.. Another recess 13-41 formed upwardly from said recess 13 provides an upper seating ledge for the nut 22-a which .co-operates with the termi nal screw 22. The nut 21a securely holds a lug 24 inelectrical connection with same, to which lug 24 is soldered or otherwise secured the lower end of the resistance coil 19. The head of the screw '23 securely holds another lug 25 in electrical connection with same, to which lug 25 is soldered or otherwise connected the upper 1 end of the resistance coil 19. A third lug 26 is held by-the nut 22a in electrical connection with same, to which lug 26 is soldered or otherwise secured an intermediate point of the resistance coil 19. A line wire terminal 27, which may take the form of a lug and screw associated therewith, is mounted within the recess 13 so as to be in electrical connection with the terminal screw 21, the lug of said terminal 27 being held by or. made integral with the nut 2l-a.

The tubular rheostat member 17 is formed at its upper end with an arcuate projection 28 extending'on'either 'side of the terminal contacts 21, 22 and 23. on said projection 28, which thus provides a space between the shell 10 and the member-.17 for proper operation of the switching means with said contact terminals 21, 22 and 23. Preferably," a centrally apertured disc of, insulating material 29 is mounted between the'shell 10 and the extreme upper end of the tubular member 17, said shell 10, disc 29 and member 17-,bein'g fixedly secured together by means of screws 30 and 31 extending longitudinally throughopenings formed through the base of the shell 10, the disc 29 and the memb er 17 including-the extension 28 The tubular member 17 is formed at its lower endwith-recesse's 32 and 34 which provide seatingledges-for the nuts 35 and 36 co-operating, respectively, with the screws 30 and'31. Another line wire terminalii'l'is disposed in one of said recesses, 34, so as to be in electrical connection thescrew 31 "and hence' with the shell 10. Said terminal 37 mayals'o take the form of a'lug and screw associated therewith, the lug being held by or made integral withthe nut 36. From the above description, it becomes apparent that there is provided an arrangement of parts in which the rheostat may be readily and rigidly secured in axial alinement' with and'to the lamp socket and inwhich the lamp" socket shell and rheostat may be reliably connected in circuit with line wires.

The insulating disc 12 is preferably mounted within the shell 10 at the bottom thereof, and carries a flexible contact strip 15 which forms an upper center contact 15 a for connection thereto with the center terminal of a lamp when inserted in the socket shell 10. A portion of this strip 15 is passed through a slot formed in the insulating disc and bent-inwardly so as to be clamped on the bottom surface of said disc 12 by the center rivet 16. The latter forms a lower center contact for co-operation with the rheostat switching 'means, the lower portion of the strip 15 and its clamping rivet 16 being disposed within the opening formed through the bottom of the shell 10; A lug 39 formed on'the bottom of the shell 10 is passed through another slot formed through the disc 12 and bent outwardly on the upper surface of the disc 12 so as to be clamped beneath the head of the screw 31. This lug 39 thus serves as initial securing means, in the process of assembly of the device, of the disc 12 to the socket shell 10, and to establish positive electrical connection betwen the socket shell 10 and the line wire terminal 37 through the medium of the screw 31. Also, this arrangement of parts, including the form of mounting the contactor 1.5 on the disc 12, insures a permanent positioning of the various conducting parts relative to one another.

In accordance with a feature of the present invention, the rheostat switching means is one adapted to engage the center contact 16 while successively engaging the rheostat contact terminals 21, 22 and 23, and thereby complete a series circuit through the rheostat and the lamp socket from a source of current to a lamp filament. Referring to the drawing, the tubular rheostat member 17 is formed at its upper end with a central recess 40 of appreciable diameter and depth, and a tubular sleeve 41 extends axially from the bottom of said recess 40 through the lower portion of the tubular member 17 to an The socket shell 10 is mounted appreciable distance below the bottom of said member 17;. The upper endof said sleeve 41 maybe formed with a nut portion 42 engaging a seat of corresponding shape formed at the bottom of the recess 40, and has its lower end threaded and provided with a lock nut 44, the latter conjunction with the nut portion 42 providing'rigid connection of the tubular sleeve 41' to the tubular; rheostat member 17. The sleeve 41 serves as a bushing or bearing for a longitudinal switch shaft 45 carrying at its upper end. switching means 46 co-operating with the center contact 16 and the rheostat terminals 21,22 and 23, and on its other end a key or knob 47 secured thereto throughthe medium of a screw 48 threaded into the lower end of said shaft.

The switching means 46 comprise two contacts 47 and 48in electrical connection with one another and co-operating, respectively, with the center contact 16 and with the'rheostat contacts '21, 22 and 23,-whereby current passage is'provided between the contact 15'aand the rheostat 11. In the formshown in the drawing, the switch contacts 47 and 48 arein the form of spring fingers extending from a common point in directions transverse to-the shaft 45, and are secured together and to a-supporting strip 49 in proximity to'this common point by a rivet 50.

The supporting strip 49 may be secured by a rivet 51 to an insulating block 52 secured-to the upper end of the shaft 45. As shownin the drawing, the insulating block 52 is inserted into a vertical slot 53 formedat the upper endofthe shaft 45, and a rivet 54" driven through said shaft 45 and block'52 secures the block 52 to the shaft 45. Preferably, a collar 55, having a portion fitted at the bottom of the aforesaid slot" 53, provides abase for the seating thereon'of the hottom of the insulating block 52, thereby insuring a firm positioning of the switching means" de-- shaft and'switchingg'means in both directions.

Evidently, the apertured insulating disc 29, intermediate'the socketshell'10 and the tubular rheostat member 1'7,- permits engagement of the arm 47 with the contact16, but insulates said arm 47 from the bottomof the shell 10.

" When an electrical nature of the general type shown in the drawing is employed, it is'usually customary to provide the connection between the lamp socket shell 10 and the main or house wiring circuit in the form of lead-in wires 59 and 60. With this form of connection, it is desirable that provision be allowed formaking the necessary wiring connections and that the socket and rheostat co-operating therewith be readily detachable from the fixture jacket 8 in order to facilitate assembling the parts in the first instance and their subsequentremoval and repair, if necessary. This object is accomplished by extending the sleeve 41 secured to the rheostat 11, through the bottom of the jacket wall and threading thereon a pair of lock nuts, 61 and 62, adapted to engage the inner and outer walls of the jacket end, respectively. To insure the correct location of the socket and rheostat relative to the jacket and hence the desired position of the nut 61 on the sleeve 41, an outer tubular spacing member 64 is inserted between thenuts 44 and 61'. The lead-in wires 59 and 60 are secured at one end to the house wiring circuit and their other ends are connected to the terminals 27 and 37. I

v Upon rotation of the shaft 45, the free end of the contact 48 is brought successively into engagement with the rheostat terminals, 21, 22 and 23, while the contact 47 is maintained in engagement with the socket contact 16. The switching means described and the socket contact co-operating therewith, by reason of the re- 'siliency of the contacts 47 and -48, provide positive engagement of the contact 48 with said terminals 21, 22 and 23, and flexibility in the assembly of the parts in that no particular atten tionis needed in theadjustment of the operating knob 47 to the bottom of the actuating shaft 45. Any tendency of loose play to shorten the life of the device aspfor example, a possible loosening of the nut 62, or of the screw 48, as the knob 47 is protractedly rotated, is thus effectively eliminated.

It now becomes apparent that, upon rotation of the shaft 45, electrical circuits will be established through lead in wire 59, terminal 27 and rheostat unit 11 .to the arm 48, and thence through the arm 4'7 to the center contact 16. Since the contactor 15 is in electrical connection with the rivet 16, current then passes through the end terminal, the filament and the'sheath of a lamp to the socket shell 10, and thence through the screw 31 to the terminal 3'] and lead-in wire 60, thereby completing a circuit for a resistance and a lamp filament in series. When the switching means are rotated to engage with the shoulder 57, the free' end of the arm 48 is on the rheostat terminal 21, and, in this position of the switching means, current is established directly from the lead-in wire 59 through the screw 31 -t0 the switching means, and the lamp will burn with full brilliancy. The arm 48 may then be caused to rotate in engagement with the rheostat terminal 22, and, in this position of the switching means, current is established from the lead-in wire 59 through the terminal 27 and lug 24 and through the lower portion of the resistance soil 1:) to the lug 26 and thence through the screw 22 to the switching means, the lamp then burning with an intermediate dimness. When the arm 48 is rotated in engagement with the rheostat terminal 23, current is established from the lead-in wire 59 through the terminal 27 and lug 24, through the complete extent of the resistance coil to the lug 25, and thence to the rheostat terminal 23 and the switching means, the lamp then burning with minimum dimness. Preferably, a small ledge 66 is formed on the upper end of the tubular member 17 in horizontal alinement with the upper surfaces of the rheostat terminals, the free end of the arm 48 slid- 'ing on this ledge to interrupt the current through by constructing the body of the rheostat of a sin gle, hollow cylindrical piece of insulating material, it is possible to wind the resistance coils directly on its exterior surface, enclose the movable parts in its central recess and rigidly securethe lamp socket to its upper end by means ofsecuring devices extending longitudinally through the body and one of which also serves to secure a wiring terminal. 7 "What is claimed'is r 1. A current reducer for electric-lamps comprising a lamp socket shell carryin'g a center contact, a stationary rheostat'body "secured in-axial alinement with said socket and having resistance windings provided withterminals disposed circularly'at the upper end of the rheostat-beneath one edge of the shell, said body having a central recess at its-upper end, a'shaft carrying switching means located in said recess and adapted to engage said'terminals upon rotation of the shaft and'providing electrical connectiontothe center contact, and lead-in terminals on the'body in electrical connection with the shell and the rheostat windings. I 2. A current reducer-for electric lamps comprising-a lamp socket carrying an insulating disc having a center contact, a tubularrheostat body secured to said socket and having resistance windingsp'rovided with terminals at its upper end, said body having a central recess at its upper end, a sleeve mountedi'n the rheostat,- a shaft within the sleeve, switching means in said recess mounted on said shaft and seatedon the upper end of the sleeve and adapted to engage "the center contact and the resistance terminals, means to limit the rotary movement of said'shaft and switching means, and circuit connections on said body in electrical contact-respectively with the rheostat and the socket shell. 4

3. A current reducer for electric lamp fixtures comprising a lamp socket shell, an insulating disc secured tosaid shell having a center contact, a rheostat disposed below said shell and disc, said rheostat comprising aresistance provided with terminals adjacent to said disc, securing devices extending through said disc for connecting said rheostat and shell, a switch arm cooperating with the rheostat terminals, means for actuating said arm, and a spring member in liaison with said means to provide electrical connection from the center contact to the switch arm and to provide pressure on said switch arm for establishing positive engagement of the switch arm with resistance terminals.

4. A current reducer for electric lamps comprising a socket embodying a shell and a center contact, an insulating block secured at one end to the bottom of said shell and having a resistance coil wound on its periphery, terminals for said coil disposed at the upper end of the block, a securing device extending through the bottom of the shell and the block for'con necting said parts together, rotary switching means adapted to engage the resistance terminals and providing electrical connection to the center contact, and lead-in terminals on the block connected to said securing device and said coil respectively.

5. A current reducer for electric lamps comprising a socket embodying a shell and a center contact, a tubular rheostat body secured at one end to the bottom of the shell and having a resistance element wound on its periphery, a plurality of screws extending longitudinally of the rheostat body and connected to predeter- ESQ mined points of the resistanceelement toipro- .videterminals at the upperrend of therheostat, a screw, extending through thebottom of the socket; shell and the, rheostat body vfor securing sai eparts. og the ,al ota y's aitlex ndi sc m trally, of the rheostat- .;and: carrying; -.switching n cansc operat s. ,W h; t e heqst t te m d-Js idcenter co t ct; a o ead-in rmi a on the rheostat secured to one or said ;first;rnentioned screws and said last mentioned-screwxespectively. z 1 l 1 .c

6.; In a. l f. fint regulator for electric lamps, Wacombinationwith a. cylindrical insulating having acentral recess and a notch provided tii s u p r ndza r q l id it e r s erminals ,on -the face otthe notch and aqrheostat W nd n on he th d q ec cd d inals, of alamp socket shellsecured tothe upper end pf the body, and having-an-insulated cen- .ter contact, a-post-journaled axially in the body, an switq em a si a v r qe rqa d y the pos t engaging;said centercontact and extending .into said notch and cooperating with the terminal contacts therein.

at:e eje t rrentz-r vl i r for e e iq lam e .sqmbi et w th a 1 cylindrical in n bodyihaving a central longitudinal opening, and mend d: h, -a,. e tt up e e at one side of tthe opening -said body being provided with a cut-away; portion in its cylindrical outer fir aeae att nda 9 ndhn the c drical ter-;surface ,of-the body, terminals for sa dzmili y eainsa d; 1 2M9 m an in P rt fl l'eiip (sa d e r w Pq n endmp tendin through the body for connecting the coil atia predetermined point thereof to a terminelta amlieec shell s r hamp an re ,t e bo n rm a r ce tris and a post journalledin said opening carrying switching means engaging the center, contact and cooperating with the terminals in said n otch. 8.;In acurrent regulator for electric lamps, the combinationlwith a cylindrical porcelain body having a central circ'ular recess provided with an inwardlyextending rib and a notch at one side: carryingfa plurality piterininals, .a resistance winding carried by said body and connected at ..various points .to said and a lamp socket shell mounted on the end of the body and provided with alcenter lamp contact, of a postrotatableaxially in said body, an in sulating carrier .in said recess and carried by the post andYco-operating with the rib' to, limit its rotary movement, and switching meansattached to said'carrier and co-operating with said center contact and said terminals.f f V ,9. In a current regulator for electric lamps, the combination with a cylindrical insulating body having at its upper end a center recess and a notch at one side of said recess, said body being provided with-a cut-away portion in its outer, cylindricalsurface, of a resistance coil wound on the outercylindrical surface of the body, terminals for said coil lying in said notch, means in part located in said cut-away portion and ,in"p'art "extending through the body 'for connecting'gthe ,eoilat a predetermined point thereof "to a terminal, a lamp socket secured at theupper endoi the body and having a center contact, and switching means in said recess cocperating ivith said center contact and said resistance terminals. l

10; ,Aicurr'ent reducerfor electric lamps comprisingfa. lamp socket embodying a shell and a center contact-at the bottom of said shell, astationary n ulating body disposed in axial alinement with said socket and having one enda'outting and secured tothe bottom of said socket, said end being formed with a lateral notch, said body also having a resistance provided with terminals disposed-at the bottom-of. said notch, and switching meansin saidbody and rotatable in the axis thereoisaid means engaging said contact and adapted to successively cooperate with the terminals;

1 1. Acurrent regulator for electric lamps comprising-alampsgclret shell, a contact member at the; bQlGtOIIlgOf said shell adaptedtoprovide electrical connection to ;the:=center contact of a lamp astatioriary ,tubular insulating body disposed in; axial alinement-with said shell and having one end abutting andsecured to the bottom of the, shell, said, end-being termed with a lateral notch, said also having a resistance woundon its, periphery and provided withterminalsdisposedpn thebottom :of said notch, resilient switching means rotatable, in the axis of the, (rheostatand cooperating with said contact member; whereby electrical connection 7 between said contact,member-and means-and positive engagement-,-of saidrmeans with said-terminals are established, an actuating shaft connected to said means and extending through said body longitudinally thereof,

12. 1; regulator for-electric lamps comprising an-electricsocket havingacenter-contact at its bottomna stationary insulating body disposed in axial valinement with said socket and having its upper end abutting and secured to the bottom of the socketsaid end being formed with a lateral recess, said body carrying a resistance having terminals laterally disposed on the bottom of saidg recess',;-resilient switching means in said recessrotatably-engaging said center contact and cooperatingwith' the resistance terminals whereby electrical connection between said center contact and said terminals and positive engagement of said means with said terminals are established, circuit connections accessible in recesses in the peripheral surface of thebody in electrical connection with the resistance and the lamp socket respectively, and means extending through the body longitudinally thereof for operating; said switching means. Y l 1 v 13. In acurrent reducer for electric lamps, the combination with a lamp socket shell and a stationary solid cylindrical. body of insulating material secured thereto and having wound exteriorly on its peripheral surface a winding of resistance wire, said: body having longitudinally extending. apertures adjacent its periphery, of a plurality oi 'conductive elongated members inserted insaid apertures providing terminalsat one end mounted on the end of the body adjacent the shelL two of said members being connected respective y to the ends of said wire, another of said members having at the other end a conductive element extending outwardly to the-periphery of the body whereby it may be connected to an intermediategpoint of said wire,a contact for one side of a current supply circuit leading directly to a member connected to one end of said wire, a center lamp circuit contact in the shell, a switch wiper cooperating with the center contact and movable into successive engagement with said terminals, and means for completing the lamp circuit through said shell.

CARL L. WEIICHELT. 

